פּירוש אויף ישעיהו 40:4

Every valley shall be raised and the mountain shall be lowered, thus resulting in a smooth, even, and easily traversed road.

Every valley shall be exalted. Every valley that is now low, shall then be exalted. The word גֶּיא valley is not in the construct state¹²From this remark it appears that I. E. read גֵּיא, and thought it therefore necessary to explain the difference between this word, used, as it seems, in the absolute state, and the same form 22:1 and Ez. 39:11 used in the construct state. No remark would have been required if I. E. had before him the reading גֶּיא adopted in the printed editions of the Bible. as in 22:1, and Ez. 39:11. It is, however, possible that it is in the construct state and some genitive is to be supplied; comp. מִלֵּיל (21:11).¹³See c. xv., Note 1.

"Every valley". He is describing how the path that is remembered which the children of exile will return on will be a straight path; the valleys and ridges will not delay them. Although it will be said that it will not be like the normal actions of the world that at the time that they want to straighten the way and a mountain and a hill and a valley is found in front of it, that then the mountain soil will travel into the valley, until the mountain is lowered and the valley is raised, in a way that according to nature a mountain and a hill will first be forced to be lowered, and because of this the valley will be filled. But if it will be that it is not by the way of nature, it will start out "Let every be raised," from itself, and afterwards, "Every hill and mountain be made low"....

and the close mountains Heb. רְכָסִים, mountains close to each other, and because of their proximity, the descent between them is steep and it is not slanted, that it should be easy to descend and ascend. ([The word] רְכָסִים is translated by Jonathan as ‘banks,’ an expression of height like the banks of a river.)

close mountains Heb. רְכָסִים. Comp. (Ex. 28:28) “And they shall fasten (וְיִרְכְּסוּ) the breastplate.”

a champaigne Canpayne in O.F., a smooth and even terrain.